1. Technical Field
The present invention relates to a system and method for providing Push To Talk (PTT) service according to the state of a user.
2. Related Art
As communication technology has developed in recent years and communication networks have become widely used, various services using communication terminals, in addition to traditional telephone service, have been provided. An example of such services is Push To Talk (PTT) service. The PTT service is unidirectional and allows group service, wherein a sender is allowed to transfer communication data, including voice data, to a receiver or a receiver group in one direction.
The PTT service is faster than telephone service since it requires a relatively simpler call establishing process. In addition, the PTT service is realized with a lower cost since it occupies a wire/wireless resource only when communication data is being transmitted. Particularly, these features enable the PTT service to be effectively used in some cases.
For example, when telephone service is used for unidirectional notice and for information delivery requiring no bidirectional communication between a sender and a receiver, time is wasted until a receiver responds and more telephone fee is generated. However, the PTT service can satisfy a user demand in a short time and at less service fee.
However, in the PTT service, since a sender transmits communication data without checking the state of the receiver, a receiver may not receive the PTT data transmitted by the sender. For example, when PTT voice data is received during the receiver's absence, the receiver cannot hear PTT voice. In order to solve this problem, a method of storing PTT voice data and then delivering it to the receiver has been conventionally used.
In the PTT system, when a PTT terminal user is absent, a PTT voice message received at the PTT terminal via a PTT server is stored in the PTT server or the PTT terminal, and a user is then notified that there is stored PTT voice data through a speaker, lamp, or the like of the PTT terminal.
However, when PTT voice data needs to be immediately delivered to the receiver, the above mentioned method, in which the data is delivered to a user later, has no effect.
Furthermore, in the PTT service, since PTT voice data is immediately sent from a sender to a receiver irrespective of the current state of the receiver, a PTT voice message is outputted through the speaker of the PTT terminal, even when the receiver is busy, thus interfering with communication.